This invention relates to compositions for the sustained release of flavorings or fragrances.
For many applications, it is desirable to provide a sustained release fragrance or flavoring composition. For example, volatile fragrances often exhibit a strong aroma for a relatively short period of time, but then exhibit little or no odor. An equivalent amount of such fragrance could be more effectively employed if small portions thereof were released into the atmosphere over a longer period of time.
Similarly, many flavorings, especially those employed in chewable substances such as chewing gums or chewing tobacco, are advantageously released in continuous, small amounts.
Various processes are known in which polymeric materials are employed in conjunction with flavorings or fragrances to form sustained release systems. For example, in U.S. Pat. Nos. 3,795,744 and 3,857,964, it is taught to form a coating of a polymeric material such as a cellulose ether around the flavoring or fragrance to be released therefrom. The flavoring or fragrance is released by the physical destruction of the polymeric coating or by the leaching of the flavoring or fragrance through the polymeric coating. Unfortunately, due to the limitations in size and physical form of such coated compositions, the use thereof is greatly restricted. In addition, the coating operation must be carefully controlled in order to obtain a product having predictable and desirable release characteristics.
Another conventionally employed sustained release system comprises forming a solid matrix of a binder material such as a cellulose ether, which matrix has dispersed therein the flavoring or fragrance to be released. While such matrix systems are somewhat useful in the preparation of pharmaceutical tablets, the size of such matrix systems often precludes the use thereof in other applications. In addition, the flavoring or fragrance is often unevenly distributed in such matrix systems, causing uneven release thereof.
Accordingly, an easily prepared sustained release system for flavorings or fragrances, which system has a physical form amenable to a variety of uses would be highly desired.